1. Field of the Invention
The present invention relates to a solid-state image sensing device and an image pickup apparatus including such a solid-state image sensing device.
2. Description of the Background Art
In recent years, there has been known a document reading apparatus including a CMOS image sensing device in which a plurality of linear pixel rows are arranged. For example, Japanese Unexamined Patent Publication No. 2007-336519 discloses a CMOS image sensor in which an arrangement pitch of three pixel rows in a column direction is 4/3 of the width W of a light receiving region in the column direction for the purpose of causing the respective pixel rows to reach the same lines of a document.
In CMOS image sensors of recent years, the sizes of the respective pixels have been reduced in response to a demand for higher resolution, miniaturization and lower cost.
However, in a conventional CMOS image sensor as disclosed in Japanese Unexamined Patent Publication No. 2007-336519, a pixel circuit including a photoelectric conversion element PD, a transfer transistor TQ, a reset transistor RQ, a floating diffusion FD, an amplifying transistor GQ and a row selection transistor SQ is arranged in each pixel as shown in FIG. 11. Thus, each pixel is taken up by the pixel circuit excluding the photoelectric conversion element PD and there is a problem of being unable to ensure a sufficient region (light receiving region) where the photoelectric conversion element PD receives light. Therefore, sufficient photons cannot be taken in, leading to a problem of reducing the sensitivity of the CMOS image sensor.